Coupling construction between extended-nip rolls

Abstract: A coupling construction between extended-nip press rolls (11,10), one of the rolls (11) in the extended-nip press comprising loading means, preferably a loading shoe, by whose means the belt mantle is loaded and the belt mantle is pressed towards the other one of the rolls (10) in the press nip, and the extended-nip press roll (11) and the back-up roll (10) being interconnected detachably. The coupling construction between the extended-nip press rolls (10,11) comprises pivotally linked tie members (14a₁,14a₂), by whose means the extended-nip press rolls (11,10) have been connected together detachably by the intermediate of their bearing housings, the tie member being connected with either one, the upper one or the lower one, of the bearing housings in the extended-nip press.

Description: The invention concerns a coupling construction between extended-nip rolls, according to the preamble of claim 1, which is based on DE-A-4219503. The nip between extended-nip rolls consists of a pair of rolls composed of SYM-ZL and SYM-BELT rolls. A special feature of such a nip is the high linear load. The linear load is at the maximum up to 1200 kN/m. In such a case, a normal screw coupling is not possible, because, in order to overcome the linear load, 130 screws per roll would be needed. In the present application, a novel solution of equipment are described for joining together of the press rolls in an extended-nip press. In the invention, it has been realized to use tie members for joining together the bearing housings of the rolls in an extended-nip press. In the solution in accordance with the invention, the tie members have been connected with the bearing-housing constructions so that, when the coupling is being uncoupled, they can be pivoted into such a position that the uncoupled roll / mantle belt / bearing can be removed. In the solution in accordance with the invention, each tie member is linked with one of the bering housings. The tie member is fitted to pivot in relation to the bearing housing and so that the end of the tie member is fitted to be locked by means of a wedge effect with the other bearing housing. The moving of the tie member takes place by means of a hydraulic cylinder. In the construction in accordance with the invention, at each roll end, two tie members are employed, and the coupling construction is symmetric in relation to the vertical central axis (Y axis) of the construction. The construction in accordance with the invention comprises an articulation point at each end of the tie member. Said solution of construction permits the tie member to be operated optionally so that the tie member is linked to be pivoted at either one of the bearing housings, either the upper or the lower bearing housing. In this way, it is possible to condition/replace either the upper bearing housing or the lower bearing housing or to condition/replace either the upper roll or the lower roll. For example, it is easy to replace the belt mantle by uncoupling the connection between the bearing housings. In the solution of equipment in accordance with the invention, the ultimate fixing of the tie member to the constructions of the bearing housing is carried out by means of screw members or equivalent. In a corresponding way, the uncoupling of the tie member from the friction joint is carried out, in the first stage, by means of screw members or equivalent. The shifting of the tie member itself apart from the bearing housing in engagement with it takes place by means of a hydraulic cylinder. The solution in accordance with the invention is sufficiently simple and, yet, operable. The coupling construction does not require a large space. In the solution, the nip forces do not have to be transferred to the frame constructions. In such a case, an expensive and spacious outside frame system is avoided. The solution is also well suitable for modernizations. The device in accordance with the invention for joining together of extended-nip press rolls is characterized that the extended-nip press rolls are joined together by their ends by means of two tie members, which tie members are placed symmetrically in relation to the vertical axis (Y axis) and which tie members can be connected optionally with either one of the bearing housings, in which case, by means of the selective coupling, either the upper bearing housing or the lower bearing housing can be removed/serviced. The invention will be described in the following with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawings, the invention being, however, not supposed to be confined to said embodiments alone. Figure 1 is a side view of an extended-nip press equipment of a paper machine / board machine. Figure 2 shows the extended-nip press equipment as viewed in the machine direction and partly in section. Figure 3A shows an extended-nip press equipment in accordance with the invention with the rolls of the extended-nip press joined together by their bearing housings. Figure 3B shows the equipment as shown in Fig. 3A as viewed in the direction of the arrow K 1 in Fig. 3A. Figure 4A is an axonometric exploded view of the parts of the coupling construction between the rolls in the equipment as shown in Figs. 3A and 3B. Figure 4B illustrates the engagement of the cylinder S with the middle frame 21a 2 and with the tie member 14a 2 . Figure 4C illustrates the engagement of the tie member 14a 2 with the frame R 2 by means of a screw, by means of which screw the tie member 14a 2 can also be detached from the engagement with the frame part R 2 . Figure 5A shows an operation stage of the device in accordance with the invention in which the lower roll can be serviced. Figure 5B shows a stage of the method in accordance with the invention in which the upper roll can be lifted off, for example, for servicing, the coupling means remaining in connection with the bearing housings of the lower roll. Fig. 1 shows an extended-nip press equipment of a paper machine. In the press equipment shown in Fig. 1, the web W is passed into the nip N between the lower extended-nip press roll 11 and the back-up roll 10 while placed between the felt H and the roll face 10' of the back-up roll 10. Fig. 2 shows the rolls 10 and 11 of Fig. 1 as viewed in the machine direction. The extended nip between the rolls 10 and 11 is denoted in the figure with the reference arrow N. The felt H and the web W are passed through the nip N. The roll 10 is a variable-crown back-up roll, and the roll 11 is an extended-nip press roll that comprises the loading means 12a 1 ,12a 2 ..., in which roll the loading means 12a 1 , 12a 2 ..., preferably cylinder means in the central axle 13, are fitted to act with a force upon the loading or glide shoe 12b and further, through the flexible closed glide-belt mantle F, upon the web W so as to remove water from the web. In the present invention, the term web W refers to a paper or board web. The lower extended-nip press roll 11 comprises a flexible closed glide-belt mantle F, which is fitted to run along the face of the loading shoe, i.e. of the glide shoe 12b, an oil medium being passed into the space between the glide shoe 12b and the closed glide-belt mantle F to constitute the lubrication medium. The back-up roll 10 may be preferably a roll heated from inside by means of a heating medium, e.g. water, steam or oil, or from outside, e.g., by means of induction or infrared heating. The back-up roll 10 may also be a non-heated roll. Fig. 3A shows a coupling construction in accordance with the invention between the rolls in an extended-nip press. In the solution of equipment, the first bearing housing 13a 1 , which is the upper bearing housing in the figure, and the second bearing housing, which is the lower bearing housing 13a 2 as shown in the figure, and, thus, the upper roll and the lower roll are interconnected by means of the tie members 14a 1 and 14a 2 . At both ends of the rolls, the bearing housings are interconnected by means of similar tie members 14a 1 and 14a 2 . Fig. 3B shows the coupling construction shown in Fig. 3A, viewed in the direction of the arrow K 1 in Fig. 3A. Fig. 4A is an axonometric exploded view of the parts of the coupling construction in an equipment in accordance with the invention. Thus, the fastening construction in accordance with the invention is symmetric in relation to the vertical axis (Y axis). The construction of the fastening construction is also substantially symmetric in relation to the second axis (X axis) perpendicular to the Y axis. The first bearing housing, which is the upper bearing housing 13a 1 as shown in Fig. 4A, includes a lifting bracket 15. The lifting bracket 15 comprises a bracket part 15a 1 , and therein a through hole 15a 2 for the loop of the lifting device, and a plate part 15a 3 connected with the bracket part 15a 1 , which plate part is attached to the frame R 1 of the bearing housing 13a 1 by means of screw means 16b 1 ...16b 4 . The screws 16a 1 ...16a 4 are passed through the screw holes 15b 1 ...15b 4 into the frame R 1 , being threaded into the threaded holes in said frame. The bearing housing 13a 1 comprises a lower fastening construction B 1 . The fastening construction B 1 is symmetric in relation to the Y axis and comprises similar fastening-construction portions B 1.1 ,B 1.2 . The frame R 1 is preferably a cast construction. The frame R 1 comprises a central opening M for the axle of the upper roll. In the figures, the bearing means on which the rolls revolve are not shown separately. The frame comprises a side face C 1 and therein a plane T 1 . On the side face C,, there is a side projection 16, comprising a face C 2 . The face planes T 1 and T 2 of the faces C 1 and C 2 are preferably parallel to one another, connected by a coupling face C 3 placed as inclined in relation to said planes. The side face C 1 comprises a screw hole 17a 1 and, in a corresponding way, the face C 2 comprises a screw hole 17a 2 ,17a 3 . The face C 1 further comprises a bracket 30a 1 ,20a 2 and therein shaft holes D 1 ,D 2 . The frame R 1 further comprises coupling means B 1.3 ,B 1.4 , which are similar to one another and which are placed at both sides of the Y axis. For example, the coupling means B 1.3 comprise a plane face T 4 and therein a projection edge 18, which comprises screw holes 19a 1 ,19a 2 as well as a keyway 20 in the bottom face. Further, the solution of equipment comprises hollow middle frames 21a 1 ,21a 2 , which are constructions similar to one another. In the following, one of said middle frames, the middle frame 21a 1 , will be described. The middle frame 21a 1 comprises an upper wall 22a 1 and a lower wall 22a 2 . Further, the solution comprises side walls 22a 3 ,22a 4 , which interconnect the upper and the lower walls perpendicularly and which comprise holes 23a 1 ,23a 2 for the shaft of the pivot cylinder S. Further, between the side walls 22a 3 ,22a 4 , there are side walls 24a 1 ,24a 2 between the upper and the lower walls 22a 1 ,22a 2 . The side walls 24a 1 ,24a 2 comprise openings 25a 1 , 25a 2 . The walls mentioned above define a hollow space E in the interior space between them, the cylinder being fitted partly in said space by its cylinder frame and so that the shaft connected with the cylinder frame is connected and linked pivotally in the axle holes 23a 1 ,23a 2 . The upper and the lower walls 22a 1 ,22a 2 project by their ends from the side walls, and their projection portions comprise screw holes 26a 1 ...26a 4 and grooves 26a 5 ...26a 8 for the screws. Moreover, the upper wall 22a 1 comprises a plane face T 5 and therein a keyway 27a 1 and, correspondingly, the lower wall part 22a 2 comprises a plane face T 6 and therein a keyway 27a 2 . In Fig. 4A, the screws are not shown separately by whose means the middle frame 21a 1 , 21a 2 is connected to its bearing housings. Further, the solution of equipment comprises adapter pieces 28a 1 ,28a 2 , which are construction parts similar to one another. For example, the adapter piece 28a 1 comprises an upper plane face T 7 and a lower plane face T 8 and keyways 29a 1 ,29a 2 in said faces. Further, the adapter piece comprises grooves 30a 1 ...30a 4 for the fitting of fastening parts, such as screws. The lower, second bearing housing 13a 2 comprises a frame R 2 , preferably a cast frame, and therein a central hole M 2 for the axle of the lower roll. The bearing housing comprises upper fastening means B 2.1 ,B 2.2 , which are constructions substantially similar to one another and which correspond to the fastening and coupling means B 1.1 ,B 1.2 of the upper bearing housing. Thus, they are constructions symmetric in relation to the central axis Y. Similarly to the upper bearing housing, said fastening means comprise a face C 1 , a second face C 2 , which has been raised in relation to said first face C 1 , and between said faces a face C 3 , which is a coupling face. The face C 3 is preferably an inclined face. Further, the face C 4 comprises a groove 300 for a bracket, and a hole 31 in the frame R 2 , whereby it is possible to pass the shaft 32 through the hole 31 and through the hole provided in the fastening bracket of the tie member, which fastening bracket is placed in the groove 300 for the bracket. The fastening means B 2.3 ,B 2.4 are constructions similar to one another and similar to the fastenings B 1.3 and B 1.4 of the upper bearing housing. Further, the lower bearing housing comprises lower fastening means B 1.5 and B 1.6 , which are similar to one another. They comprise a plate 33b and therein grooves 33a 1 ...33a 4 for screws, by whose means the construction is fixed to the machine foundation P. At the ends of the rolls, interconnecting the bearing housings, there are two similar tie members 14a 1 and 14a 2 . Each tie member 14a 1 ,14a 2 comprises a middle frame 34a 1 and, at both of its ends, side frames 34a 2 ,34a 3 , whose longitudinal axes are substantially perpendicular to the longitudinal axis Z 1 of the middle frame. The tie members 14a 1 , 14a 2 are symmetric in relation to the central axis X'. Each tie member comprises an articulation point N 1 ,N 2 at its ends, in which case the tie member can be connected optionally with either one of the bearing housings. At each end of the middle frame 34a 1 , there is a bracket 35a 1 ,35a 2 . The bracket 35a 1 includes a hole 36, through which the shaft 37 can be passed, in which case the tie member can be coupled, with an articulated joint, with one of the bearing housings by means of said shaft 37. In a corresponding way, the other end of the tie member comprises a similar bracket construction 35a 2 , by whose means the tie member can be coupled optionally, with an articulated joint, with the other bearing housing. Further, the tie member 14a 1 , 14a 2 comprises a handle, by whose means the tie member can be displaced by making use of an outside device. The middle frame 34a 1 of the tie member comprises a central opening 38 passing through the middle frame. At both sides of the opening 38, there are brackets 39a 1 ,39a 2 . The brackets 39a 1 ,39a 2 comprise through holes 40a 1 ,40a 2 for a shaft, whereby the pivot cylinder S can be coupled with the tie member by the end of the piston rod. Inside the U-section, the side frames 34a 2 ,34a 3 comprise a wedge piece 41 of tin bronze, whose coupling face D' is preferably a cylindrical face. Further, the middle frame 34a 1 comprises screw holes 42a 1 ,42a 2 and 42a 3 , of which holes, tightening screws 43a 1 ,43a 2 are passed through the holes 42a 1 ,42a 2 , and of which holes, a detaching and tightening screw 43a 3 is passed through the hole 42a 3 . Fig. 4B is an illustration on an enlarged scale of the engagement of the tie member 14a 1 with the cylinder device S. The cylinder S, which is preferably a hydraulic cylinder, is further coupled by its cylinder frame S' with the middle frame 21a 1 . The middle frames 21a 1 and 21a 2 can be coupled by separate screw means (not shown) both with the upper bearing housing 13a 1 and with the lower bearing housing 13a 2 . The coupling mentioned above also permits that the tie members 14a 1 ,14a 2 can be coupled operationally either with the upper bearing housing or with the lower bearing housing. When the tie member 14a 2 , 14a 1 is linked to pivot in relation to the upper bearing housing 13a 1 , when the coupling between the rolls is being uncoupled, the coupling means connected with the middle frame 21a 1 ,21a 2 are detached from the lower edge of the middle frame 21a 1 ,21a 2 (in Fig. 4B, said edge is denoted with O 1 at the part 21a 2 ), and similarly, if the tie member 14a 1 ,14a 2 is linked to pivot in relation to the lower bearing housing 13a 2 , when the coupling between the rolls is being uncoupled, the bearing means at the edge O 2 are detached from the engagement with the upper bearing housing at the edge O 2 . Thus, the detachable middle frame 21a 1 ,21a 2 permits the above selective operation. Fig. 4C shows the engagement of the tie member 14a 2 with the frame R 2 by means of the screw 43a 3 . The screw 43a 3 is passed through the screw hole 42a 3 placed in the tie member 14a 2 into the threaded hole 101 in the frame R 2 . The screw 43a 3 comprises a flange 102. The tie member 14a 2 comprises a recess 105 in one of its faces, the flange 102 of the screw 43a 3 being placed in said recess. When the screw 43a 3 is threaded in one direction, the head 106 of the screw is threaded into contact with the plate part 103, and the tie member 14a 2 is pressed into contact with the frame R 2 . When the member 14a 2 is detached from the engagement with the frame R 2 the screw 43a 3 is threaded in the opposite sense, in which case the flange 102 of the screw 43a 3 , when pressed against the lower face of the part 103, lifts the tie member 14a 2 apart from the frame R 2 . The part 103 is fixed to the member 14a 2 by means of screws 104. Fig. 5A shows a solution of equipment in accordance with the invention in an operation stage in which the tie members 14a 1 ,14a 2 are linked pivotally with the upper bearing housing and in which solution of equipment the tie members 14a 1 ,14a 2 are kept by means of the cylinder device S in a so-called open position, in which case the lower roll and the lower bearing housing can be conditioned/detached. Fig. 5B shows a coupling construction in accordance with the invention in a mode of operation in which the tie members 14a 1 ,14a 2 are linked pivotally with the lower bearing housing and in which said tie members are kept in a so-called open position by means of the cylinder device S. By means of the cylinder device S, the tie members are brought close to the bearing housing to be coupled, and the ultimate fixing and pressing of the tie member against its back-up face takes place by means of separate screw means.

Claims: Coupling construction between extended-nip press rolls (11,10), one of the rolls (11) in the extended-nip press comprising loading means, preferably a loading shoe, by whose means the belt mantle is loaded and the belt mantle is pressed towards the other one of the rolls (10) in the press nip, and the extended-nip press roll (11) and the back-up roll (10) being interconnected detachably by tie members (14a 1 ,14a 2 ), by the intermediate of the bearing housings of said extended-nip rolls (10,11), characterized in that the tie members (14a 1 ,14a 2 ) are pivotally connected with either one, the upper one or the lower one, of the bearing housings in the extended-nip press. Coupling construction as claimed in claim 1, characterized in that the bearing housings at each end of the rolls are interconnected by two tie members, the tie members (14a 1 ;14a 2 ), detachably, each pair of tie members being connected with the same bearing housing by their articulation points (N 1 or N 2 ), and that in coupling situations the tie members have been pressed, by one of their ends, into contact with the other bearing housing to be joined together, against the coupling face of said bearing housing. Coupling construction as claimed in any of the preceding claims, characterized in that, at each end of the rolls, the tie members (14a 1 ,14a 2 ) are placed symmetrically in relation to the vertical axis (Y axis). Coupling construction as claimed in any of the preceding claims, characterized in that there is a separate pivot cylinder (S), which is by one end coupled with a middle frame between the bearing housings and by the other end with the tie member (14a 1 ,14a 2 ). Coupling construction as claimed in the preceding claim, characterized in that there is a middle frame (21a 1 ,21a 2 ), which comprises a hollow inside space (E), the pivot cylinder (S) being, by one end, connected by means of an articulated joint, with the middle frame, while the pivot cylinder (S) is, at least partly, placed in the hollow inside space (E) in the middle frame. Coupling construction as claimed in any of the preceding claims, characterized in that each tie member (14a 1 ,14a 2 ) comprises a symmetry axis (X' axis), and that the tie member (14a 1 ,14a 2 ) comprises articulation points (N 1 ,N 2 ) correspondingly at each end of the middle frame (34a 1 ) of the tie member (14a 1 , 14a 2 ). Coupling construction as claimed in the preceding claim, characterized in that there is a bracket (35a 1 ,35a 2 ) or equivalent, through which the shaft (37) can be passed so as to connect the tie member (14a 1 ,14a 2 ) with the bearing housing (13a 1 or 13a 2 ) by means of an articulated joint. Coupling construction as claimed in any of the preceding claims, characterized in that the tie member (14a 1 ,14a 2 ) comprises a middle frame (34a 1 ) and, at both ends of said middle frame, side frames (34a 2 ,34a 3 ), whose longitudinal axes are substantially perpendicular to the longitudinal axis (Z 1 ) of the middle frame and which side frames comprise, on the inner faces of the U-section thus formed, a coupling piece (41), preferably a coupling piece of tin bronze, whose coupling face (D') can be wedged into contact with the counter-coupling face (C 3 ) provided on the side face of the bearing housing. Coupling construction as claimed in any of the preceding claims, characterized in that each tie member (14a 1 ,14a 2 ) comprises screw holes (42a 1 ,42a 2 , 42a 3 ), of which holes, through the holes (42a 1 ,42a 2 ), tightening screws (43a 1 ,43a 2 ) have been passed and, of which holes, through the hole (42a 3 ), a detaching and tightening screw (43a 3 ) has been passed, in which case, by means of said screws, the tie member can be coupled with the bearing housing detachably, one set of screws operating as tightening screws, and at least one such screw being provided as operates as a detaching screw. Coupling construction as claimed in any of the preceding claims, characterized in that the cylinder (S) is a hydraulic cylinder, by whose means the tie member (14a 1 , 14a 2 ) is brought apart from the bearing housing that was coupled with said tie member and by whose means the tie member (14a 1 , 14a 2 ) is brought into connection with the bearing housing to be coupled with said tie member. Coupling construction as claimed in any of the preceding claims, characterized in that the tie member (14a 1 ,14a 2 ) comprises a through opening (38) and, in connection with said opening, coupling means, by whose intermediate the cylinder (S) can be coupled with the tie member (14a 1 ,14a 2 ).

Inventors: VALLIUS OIVA, VALLIUS, OIVA
Applicants: VALMET CORP, VALMET CORPORATION
Application year: 1994
Main classification: D21F3
IPC codes: D21F3, D21F7